Ga-hybridization-mediated broadband optical amplification in Bi-activated photonic glass and fiber.

A Ga hybridization strategy is proposed for simultaneously enhancing the near-infrared activity and extending the bandwidth of Bi-activated photonic glass. Systematic studies on the near-infrared optical responses of Ga/Bi and Al/Bi co-doped silica glasses are performed. It is interesting to note that Ga/Bi co-doped glasses have a similar near-infrared emission center to Al/Bi co-doped glass, while the former is more effective in improving near-infrared activity. The different luminescence mechanisms of Ga/Bi and Al/Bi co-doped silica glasses are elucidated, and the corresponding microstructure-optical response relationship is discussed. In addition, the Ga/Bi co-doped silica optical fiber is successfully prepared, and the principal fiber amplifier device is fabricated. Furthermore, amplified spontaneous emission and broadband on-off gain are realized. The results suggest that Ga-hybridized Bi-activated photonic glass is a promising gain material for broadband fiber amplifiers.

Single-frequency fiber laser at 1627†nm based on a self-designed Er-doped hybridized glass fiber.

Aiming at applications like expanding usable wave band of optical telecommunication and preparing Sr optical lattice clocks, a 1627 nm single-frequency fiber laser (SFFL) is demonstrated based on a 7-m-long self-designed Er-doped hybridized glass fiber (EDHF) and a linear cavity configuration with a loop mirror filter (LMF). By inserting a 10-m-long unpumped commercial Er-doped fiber as a dynamic Bragg grating into the LMF, a stable single-longitudinal-mode (SLM) laser with an output power of about 10 mW is obtained. The optical signal-to-noise ratio (OSNR) of SFFL is over 50 dB, and the linewidth is about 3.7 kHz. The measured relative intensity noise (RIN) is less than -140 dB/Hz at frequencies of over 0.5 MHz, and a power variation in 1 h is less than ±0.26%. To our best knowledge, it is the first demonstration of a SFFL operating at the U-band. This 1627 nm SFFL can provide advanced light source technology support for many cutting-edge applications.

The therapeutic efficacy and safety of intravenous immunoglobulin in dermatomyositis and polymyositis: A systematic review and meta-analysis.

OBJECTIVES: To evaluate the efficacy and safety of intravenous immunoglobulin (IVIG) in the treatment of dermatomyositis (DM) and polymyositis (PM). METHODS: We searched PubMed, Embase, and the China National Knowledge Infrastructure for relevant studies from July 1919 to May 2021. RESULTS: Seventeen papers pertinent to our questions were found: In a meta-analysis, we found that IVIG significantly improved the level of CK (SMD (STD. Mean Difference) = -0.69; 95%CI -0.93, -0.46; P < 0.0001), Manual Muscle Test (SMD = 1.12; 95%CI 0.77, 1.47; P < 0.00001), Medical Research Council (SMD = 1.59; 95%CI 0.86, 2.33; P < 0.00001), Activities of Daily Living (SMD = 1.07; 95%CI 0.59, 1.56; P < 0.0001). The CK levels in DM and PM were also significantly improved after IVIG (SMD = -0.73; 95%CI -1.12, -0.34; P = 0.0002 and SMD = -3.29; 95%CI -5.82, -0.76; P < 0.0001, respectively). The meta-analysis of three RCTs showed that there was a statistically significant improvement after IVIG (SMD = 0.63; 95%CI 0.22, 1.03; P = 0.002). In a random effects model, pooled muscle power improvement rate was 77% (95% CI: 66.0-87.0%). Meta-analyses of IVIG as first-line therapy showed a significant improvement of the CK level (SMD = -0.71; 95%CI -1.12, -0.30; P = 0.0007). The polled improvement rate of oesophageal disorders was 88% (95% CI: 80.0-95.0%). There was no statistically significant difference in the rate of improvement between the number of courses <2 and ≥2 (0.80% vs. 0.80%, P = 0.9). The proportion of corticosteroid-sparing success reached 81.8%. Adverse reactions following IVIG administration are usually mild and transient. Seven patients developed serious adverse events. CONCLUSION: IVIG seems to be an effective drug for DM/PM, improving muscle strength, CK levels, and oesophageal involvement, and it is well tolerated by patients.

Cardiovascular events in adult polymyositis and dermatomyositis: a meta-analysis of observational studies.

OBJECTIVES: We aimed to review whether PM and DM patients have an increased cardiovascular (CV) risk, including ischaemic heart disease (IHD), cerebrovascular accidents (CVA) and venous thromboembolism. METHODS: We searched PubMed, Embase and the Cochrane database for relevant studies from inception to February 2021. RESULTS: Twenty-two studies comprising 25 433 patients were included. With PM/DM vs general populations, the risk was significantly increased for CV events [relative risk (RR) = 2.37, 95% CI: 1.86, 3.02]. The RR of CV events for males with PM/DM was higher than for females (RR = 1.43; 95% CI: 1.17, 1.74). PM/DM patients followed for one to five years had a significantly higher CV risk than those followed for five to ten years (RR = 3.51, 95% CI: 1.95, 6.32). The risk was increased for North Americans (RR = 4.28, 95% CI: 2.57, 7.11), Europeans (RR = 2.29, 95% CI: 1.58, 3.31) and Asians (RR = 2.03, 95% CI: 1.41, 2.90). Our meta-analysis found that the elevated CV event risk was related to PM (RR = 2.35, 95% CI: 1.51, 3.66) and DM (RR = 2.55, 95% CI: 1.66, 3.93). Subgroup analyses showed that the risk was significantly increased for IHD (RR = 1.76, 95% CI: 1.40, 2.21), CVA morbidity (RR = 1.31, 95% CI: 1.03, 1.67) and ischaemic stroke (IS) (RR = 1.47, 95% CI: 1.26, 1.73), with no statistically significant increased risk of haemorrhagic stroke mortality (RR = 1.43, 95% CI: 0.92, 2.21). The CV event risk was increased for venous thromboembolism (RR = 4.60, 95% CI: 3.17, 6.66), deep venous thrombosis (RR = 5.53, 95% CI: 3.25, 9.39) and pulmonary embolism (RR = 5.26, 95% CI: 2.62, 10.55). CONCLUSION: This meta-analysis found that PM/DM patients had a ∼2.37 times increased CV risk, particularly males diagnosed in the previous five years. PM/DM may be an independent risk factor for developing IHD, IS, deep venous thrombosis and pulmonary embolism.

Thermally stable gold nanorod dispersed silicone composite with plasmonic resonance in the optical communication window.

Gold nanorods (AuNRs) possess a high optical nonlinear coefficient, ultrafast optical response speed and widely tunable localized surface plasmon resonance (LSPR) wavelength covering the visible and near infrared region. Therefore, they are extensively investigated for many optical applications. However, the poor thermal stability of the AuNRs seriously restricts their practical performance. In addition, for many applications, such as optical communication or laser modulation, AuNRs have to be combined with transparent solids, for example polymers, glass or crystals to make devices. Here, we report on the preparation of 0.23 mg AuNR dispersed methyl silicone resin (MSR) with longitudinal LSPR (L-LSPR) wavelength (1450 nm) in the optical communication window. We found that AuNR-silicone composites possess high thermal stability. After calcination in ambient environment at a temperature of 250 °C for 10 h, the L-LSPR peak of the sample can remain longer than 1380 nm, implying that the NR shape of the Au particles was well maintained. Using the open-aperture Z-scan technique, the nonlinear absorption coefficient of the composites was measured as -11.71 cm GW-1, higher than many nonlinear materials. Thus, the thermally stable AuNR@SiO2-MSR composite with high nonlinearity is promising for practical applications in the optical communication window.

Angiotensin-converting enzyme inhibitors prior to scleroderma renal crisis in systemic sclerosis: A systematic review and meta-analysis.

WHAT IS KNOWN AND OBJECTIVE: Angiotensin-converting enzyme inhibitors (ACEIs) are widely used in the treatment of scleroderma renal crisis (SRC), and their use prior to the onset of SRC in patients with systemic sclerosis (SSc) has received wide attention in recent years. We undertook an evidence-based approach to identify whether the use of ACEIs prior to the onset of SRC is beneficial for patients with SSc. METHODS: We searched PubMed and Embase for any published studies produced between database inception and 22 October 2021. Articles obtained after using appropriate keywords were selected independently by two reviewers according to the established inclusion and exclusion criteria. RESULTS: Nine studies were included. Pooled results indicated that using ACEIs prior to SRC was associated with a higher incidence of SRC than no ACEIs prior to SRC (RR 2.05, 95% confidence interval 1.08-3.91, p = 0.03). Compared with patients who did not use ACEIs prior to the onset of SRC, a higher proportion of patients with SRC who used ACEIs prior to its onset had a poorer prognosis (RR 1.46, 95% confidence interval 1.20-1.78, p < 0.01). The difference in mortality between patients who used ACEIs prior to SRC onset and those who did not was not statistically significant (RR 1.12, 95% confidence interval 0.76-1.65, p = 0.57). WHAT IS NEW AND CONCLUSIONS: We recommend against using ACEIs prior to SRC in SSc patients. The use of ACEIs prior to SRC is associated with a higher incidence of SRC and poorer prognosis, especially in patients with progressive SSc or SSc-related renal vasculopathy (SSc-related hypertension and proteinuria).

Visualized thermal history sensor based on the rare-earth-doped zirconia.

Temperature is one of the most fundamental parameters, and its accurate measurement is critically important for thermal systems. Despite substantial progress in temperature measuring techniques, design and fabrication of a reliable thermal history sensor, which can remember thermal events, still remain a significant challenge. In this Letter, we propose and experimentally demonstrate a new thermal history sensor based on the rare-earth-activated and yttria-stabilized zirconia (YSZ). This material candidate exhibits strong heat-treatment-dependent upconversion emission color. The structure and optical characterizations indicate that the phenomenon originates from the cooperative effects of multiple physical parameters, including crystallinity, crystal size, and the quantity of residual OH. This allows us to achieve excellent linear relationship between the heat-treatment temperature and the intensity ratio of the green and red emission band over a wide temperature range from 800°C to 1350°C. Thus, the thermal history information can be directly judged based on the emission color. These results provide a major step forward in expanding the scope of thermal history sensor materials.

Naringin alleviates H2O2-induced apoptosis via the PI3K/Akt pathway in rat nucleus pulposus-derived mesenchymal stem cells.

Purpose: To investigate the protective effect of naringin (Nar) on H2O2-induced apoptosis of nucleus pulposus-derived mesenchymal stem cells (NPMSC) and the potential mechanism in this process. Methods: Rat NPMSC were cultured in MSC culture medium or culture medium with different concentrations of H2O2. Nar or the combination of Nar and LY294002 was added into the culture medium to investigate the effects of Nar. Cell viability was evaluated by cell counting kit-8 (CCK-8) assay. The apoptosis rate was determined using Annexin V/PI dual staining and terminal deoxynucleotide transferase-mediated dUTP nick end labeling (TUNEL) assays. Additionally, the levels of reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) were analyzed by flow cytometry. ATP level in NPMSC was analyzed via ATP detection kit. Mitochondrial ultrastructure change was observed through transmission electron microscope (TEM). Levels of apoptosis-associated molecules (cleaved caspase-3, Bax and Bcl-2) were evaluated via RT-PCR and western blot, respectively. Results: The cells isolated from NP met the criteria for MSC. H2O2 significantly promoted NPMSC apoptosis in a dose and time-dependent manner. Nar showed no cytotoxicity effect on NPMSC up to a concentration of 100 µM for 24 h. Nar exhibited protective effects against H2O2-induced NPMSC apoptosis including apoptosis rate, expressions of proapoptosis and antiapoptosis related genes and protein. Nar could also alleviate H2O2-induced mitochondrial dysfunction of increased mitochondrial ROS production, reduced MMP, decreased intracellular ATP and mitochondrial ultrastructure change. However, these protected effects were inhibited after LY294002 treatment. Conclusions: Our results demonstrated that Nar efficiently attenuated H2O2-induced NPMSC apoptosis and mitochondrial dysfunction. The activation of ROS-mediated PI3K/Akt pathway may be the potential mechanism in this process.

The effect of high glucose on the biological characteristics of nucleus pulposus-derived mesenchymal stem cells.

Diabetes mellitus (DM) is a dependent risk factor in the progression of intervertebral disc degeneration (IVDD). High glucose supply has negative effects on nucleus pulpous (NP) cell and mesenchymal stem cell (MSC) biology. However, the effect of hyperglycaemia on the biological characterization of nucleus pulpous-derived mesenchymal stem cell (NPMSC) has not been investigated previously. Therefore, further exploration of the effects of DM-associated hyperglycaemia on NPMSC biology is important to better understand and develop endogenous repair strategies of DM patient-associated IVDD. Therefore, the cell biological characteristics were compared between NPMSC cultured in media with low glucose concentration (LG-NPMSC) and high glucose concentration (HG-NPMSC). The results demonstrated that HG-NPMSC showed significantly decreased cell proliferation, colony formation ability, migration and wound-healing capability compared with those of LG-NPMSC. HG-NPMSC also showed significantly decreased expressions of stemness genes and mRNA and protein expressions of silent information regulator protein 1 (SIRT1), SIRT6, hypoxia inducible factor-1α (HIF-1α) and glucose transporter 1 (GLUT-1), whereas increased cell apoptosis, cell senescence and caspase-3 expression. These results suggest that high glucose may decrease proliferation and stemness maintenance ability and increase apoptosis and senescence of NPMSC. SIGNIFICANCE OF THE STUDY: We found that high glucose concentration significantly decreased cell proliferation, colony formation ability, migration and wound-healing capability of nucleus pulposus-derived mesenchymal stem cells. Moreover, high glucose cultured nucleus pulposus-derived mesenchymal stem cells showed significantly decreased expression of stemness genes, related mRNA and protein, whereas increased cell apoptosis, cell senescence and expression of caspase-3. The present study indicated that better control of high concentration glucose in the early stage of diabetes mellitus should be recommended to prevent or limit intervertebral disc degeneration.

Gain-guided soliton: Scaling repetition rate of passively modelocked Yb-doped fiber lasers to 12.5 GHz.

Fundamental repetition rates of 3.1 GHz, 7.0 GHz, and 12.5 GHz in passively modelocked Yb-doped fiber lasers are demonstrated. To the best of our knowledge, the fundamental repetition rate of 12.5 GHz is the highest value for 1.0 µm mode-locked fiber lasers. The mode-locked oscillator has a peak wavelength of 1047.5 nm and a pulse duration of 1.9 ps. The repetition rate signal has a signal-to-noise ratio of 57 dB. The peak wavelength of mode-locked spectra gradually makes a blue-shift and the modelocked threshold power increases with an increase in pulse repetition rate. Furthermore, in contrast to most of the all-normal-dispersion mode-locked fiber lasers, the present linear resonator (e.g., length < 1 cm) allows the buildup of gain-guided soliton without any filter effect. To unveil the underlying pulse shaping mechanism, a combined model comprising dynamic rate equations and the generalized nonlinear Schrödinger equation is established. Surprisingly, an essential gain filtering effect, which is contributed by a 26-nm gain bandwidth, is revealed and can verify the gain-guided pulse dynamics. Moreover, the pulse build-up in temporal and frequency domain, like spectral evolution and gain bandwidths, is numerically carried out in detail.

The effect of intervertebral disc degenerative change on biological characteristics of nucleus pulposus mesenchymal stem cell: an in vitro study in rats.

Purpose: To evaluate the change on biological characteristics of mesenchymal stem cell (MSC) derived from normal and degenerative intervertebral disc (IVD). Methods: MSC was isolated from normal and degenerative IVD rat model. Immunophenotype detected by flow cytometric analysis, expression of stemness genes determined by reverse-transcription polymerase chain reaction (RT-PCR) and osteogenic, adipogenic and chondrogenic differentiation were compared between MSC derived from normal IVD (N-NPMSC) and degenerative IVD (D-NPMSC). The biological characteristics including cell proliferation, colony formation, apoptosis, caspase-3 activity and mRNA and protein expressions of hypoxia inducible factor-1α (HIF-1α), glucose transporter 1 (GLUT-1), vascular endothelial growth factor (VEGF), silent information regulator protein 1 (SIRT1) and silent information regulator protein 6 (SIRT6) were compared between N-NPMSC and D-NPMSC. Results: Both of N-NPMSC and D-NPMSC highly expressed CD105, CD90 and CD73, and lower expressed CD34 and CD45. There was no significant difference in cell morphology and multipotent differentiation ability between N-NPMSC and D-NPMSC. D-NPMSC showed significantly lower expressions of stemness genes, cell proliferation and colony formation ability. D-NPMSC also exhibited increased cell apoptosis rate and caspase-3 expression, and significantly lower expressions of HIF-1α, GLUT-1, VEGF, SIRT1 and SIRT6 in mRNA and protein levels compared with N-NPMSC. Conclusions: N-NPMSC showed significantly higher proliferation rate, better colony forming and stemness maintenance ability, whereas reduced cell apoptosis rate compared with D-NPMSC. HIF-1α-mediated signal pathway may be involved in the regulation of NPMSC proliferation. These findings indicated that degenerative change of IVD should be taken into account when selecting a source of NPMSC for clinical application.

Graphene-based polarization-sensitive longwave infrared photodetector.

We demonstrated a polarization-sensitive photodetector based on periodically crossed graphene ribbons theoretically. Localized surface plasmon is generated by patterned graphene structure with significantly enhanced incident light absorption. Broadband detection is observed from 10.5 to 16.5 µm. Moreover, the photoresponsivity reaches up to 1.717 A W-1 at the wavelength of 12.58 µm under 0° polarization, and the photoresponsivity is 0.212 A W-1 under 90° polarization. The tunability of photodetectors is achieved by changing the gate voltage to modulate the chemical potential of graphene. The finite difference time domain solutions are used to predict the performance of the photodetector with different polarization angles for longwave infrared (LWIR) light. The polarization-sensitive, tunable and broadband graphene photodetector provides a promising direction for high performance LWIR detection at room temperature.

Crystallization control toward colorless cerium-doped scintillating glass.

The construction of cerium-doped materials is of great technological importance for various applications, including smart lighting, biological shielding and high-energy ray and particle detection. A major challenge is the efficient prevention of the undesired colorization after cerium doping. Here we present the nanocrystallization method for constructing colorless cerium-doped glass with extremely high cerium concentration (15 mol%). The structure and optical characterizations confirm that the notable color change of glass is associated with the precipitation of CeF3 crystalline phase during heat-treatment. The chemical state investigation shows that most of cerium ions exist in the form of Ce3+ in both the glass and glass-ceramic samples. The chemical environment study indicates a dramatic change in the local structure unit from -Ce-O- to -Ce-F-, which is believed to dominate the decoloring phenomenon in cerium doped glass. As a result, a significant improvement in the ultraviolet excited luminescence (~35 times enhancement in intensity) and scintillating performance can be achieved, pointing to potential applications in X-ray detection.

Fabrication of microchannels by space-selective control of phase separation in glass.

Microchannels have important scientific applications in many fields, because they enable precise control, manipulation, and analysis of fluid on a micrometer scale. Herein, we demonstrate an effective strategy for fabrication of microchannels, based on the space-selective phase separation in glass induced by a femtosecond laser. The proposed method shows its abilities in fabrication of three-dimensional microchannels with ∼5 mm length scale and a uniform cross section. Moreover, we also achieve the modulation of the morphology on the inner surface of microchannels by using objective lenses with various numerical-apertures. The physical mechanism of the phase separation and microstructure evolution is discussed. Our method provides new opportunities to fabricate microchannels with complex structures and multifunctional integration.

Ni(2+) doped glass ceramic fiber fabricated by melt-in-tube method and successive heat treatment.

Glass ceramic fibers containing Ni(2+) doped LiGa(5)O(8) nanocrystals were fabricated by a melt-in-tube method and successive heat treatment. Fiber precursors were prepared by drawing at high temperature where fiber core glass was melted while fiber clad glass was softened. After heat treatment, LiGa(5)O(8) nanocrystals were precipitated in the fiber core. Excited by 980 nm laser, efficient broadband near-infrared emission was observed in the glass ceramic fiber compared to that of precursor fiber. The melt-in-tube method can realize controllable crystallization and is suitable for fabrication of novel glass ceramic fibers. The Ni(2+)-doped glass ceramic fiber is promising for broadband optical amplification.

[Changes of HCN4, Cx43 Expression in the Sinoatrial Node of Electric Shock Death].

OBJECTIVE: To investigate the expression of hyperpolarization-activated cyclic nucleotide-gated cation channel 4 (HCN4) and connexin43 (Cx43) in the sinoatrial node of electric shock death. METHODS: As experimental group, 34 cases of electric shock death who had definite current mark evidence were selected from pathology department of Xuzhou Medical College from 2010 to 2013. As the control group, 20 cases of fatal severe craniocerebral injury in traffic accidents were chosen. The expressions of HCN4 and Cx43 in the sinoatrial node were observed by immunohistochemical technology. RESULTS: HCN4 positive cells expressed in the cell membrane and cytoplasm of the sinoatrial node. Cx43 positive cells expressed in the cell membrane and cytoplasm of T cells and myocardial cells. The expression of HCN4 was significantly higher than that of the control group (P < 0.05) and the expression of Cx43 was significantly lower than that of the control group (P < 0.05). CONCLUSION: The changes of HCN4 and Cx43 expressions in the sinoatrial node illustrate electric shock death might be related to the abnormalities of cardiac electrophysiology and conduction.

Space-selective precipitation of ZnO crystals in glass by using high repetition rate femtosecond laser irradiation.

We report on three-dimensional (3D) precipitation of ZnO crystals inside a silicate glass by a 500 kHz femtosecond pulse laser. The precipitation and distribution of ZnO crystals in glass are confirmed and analyzed by Raman spectra and Raman mapping. Mirco- luminescence is observed in the laser modified region when excited by femtosecond pulse laser or Xenon lamp. The effect of laser average power on the precipitation of the ZnO crystals has also been investigated. The possibility of 3D optical data storage using the observed phenomena is demonstrated.

Origin of structural relaxation dependent spectroscopic features of bismuth-activated glasses.

For the first time, we studied the effect of structural relaxation on the NIR spectroscopic properties of bismuth-activated germanium glasses below glass transition temperature. Interestingly, distinct change behavior of NIR luminescence is observed at two different heat-treatment temperature ranges corresponding to two different relaxation behavior of glass structure. Besides, when structural modified by partly substituting B(2)O(3) for GeO(2), a narrower and more thermal sensitive luminescence is observed, which is inexplicable by "inhomogeneous broadening" and we tentatively attribute it to a defect-involved reason. Fundamentally the results here not only provide us a deeper insight into the optical property of bismuth-activated materials but also increase our understanding of the glassy state, and practically it delivers some valuable guidance in designing bismuth-activated glasses with superior NIR optical properties.

Enhanced broadband excited upconversion luminescence in Ho-doped glasses by codoping with bismuth.

We report enhanced green and red upconversion (UC) luminescence in Ho3+-doped oxyfluoride germanate glass by introducing bismuth near-infrared active centers as sensitizers. The UC excitation bands at 750 and 970 nm show a full width at half-maximum of 20 and 45 nm, respectively. Energy transfer from sensitizers, the excited-state absorption, and phonon-coupled absorption of Ho3+ jointly contribute to the enhanced UC luminescence. Our approach provides an efficient methodology to broaden the excitation bandwidth of UC luminescent materials, which may have the potential for promising application in solar cells.